Featured Research

from universities, journals, and other organizations

Tibetan Plateau was larger than previously thought, geologists say

Date:

April 11, 2014

Source:

Syracuse University

Summary:

The Tibetan Plateau -- the world's largest, highest, and flattest plateau -- had a larger initial extent than previously documented, Earth scientists have demonstrated. Known as the "Roof of the World," the Tibetan Plateau covers more than 970,000 square miles in Asia and India and reaches heights of over 15,000 feet. The plateau also contains a host of natural resources, including large mineral deposits and tens of thousands of glaciers, and is the headwaters of many major drainage basins.

Share This

Known as the "Roof of the World," the Tibetan Plateau covers more than 970,000 square miles in Asia and India and reaches heights of over 15,000 feet. Hoke's discovery not only makes the plateau larger than previously thought, but also suggests that some of the topography is millions of years younger.

Earth scientists in Syracuse University's College of Arts and Sciences have determined that the Tibetan Plateau -- the world's largest, highest, and flattest plateau -- had a larger initial extent than previously documented.

Related Articles

Their discovery is the subject of an article in the journal Earth and Planetary Science Letters (Elsevier, 2014).

Gregory Hoke, assistant professor of Earth sciences, and Gregory Wissink, a Ph.D. student in his lab, have co-authored the article with Jing Liu-Zeng, director of the Division of Neotectonics and Geomorphology at the Institute for Geology, part of the China Earthquake Administration; Michael Hren, assistant professor of chemistry at the University of Connecticut; and Carmala Garzione, professor and chair of Earth and environmental sciences at the University of Rochester.

"We've determined the elevation history of the southeast margin of the Tibetan Plateau," says Hoke, who specializes in the interplay between Earth's tectonic and surface processes. "By the Eocene epoch (approximately 40 million years ago), the southern part of the plateau extended some 600 miles more to the east than previously documented. This discovery upends a popular model for plateau formation."

Known as the "Roof of the World," the Tibetan Plateau covers more than 970,000 square miles in Asia and India and reaches heights of over 15,000 feet. The plateau also contains a host of natural resources, including large mineral deposits and tens of thousands of glaciers, and is the headwaters of many major drainage basins.

Hoke says he was attracted to the topography of the plateau's southeast margin because it presented an opportunity to use information from minerals formed at Earth's surface to infer what happened below them in the crust.

"The tectonic and topographic evolution of the southeast margin has been the subject of considerable controversy," he says. "Our study provides the first quantitative estimate of the past elevation of the eastern portions of the plateau."

Historically, geologists have thought that lower crustal flow -- a process by which hot, ductile rock material flows from high- to low-pressure zones -- helped elevate parts of the plateau about 20 million years ago. (This uplift model has also been used to explain watershed reorganization among some of the world's largest rivers, including the Yangtze in China.)

But years of studying rock and water samples from the plateau have led Hoke to rethink the area's history. For starters, his data indicates that the plateau has been at or near its present elevation since the Eocene epoch. Moreover, surface uplift in the southernmost part of the plateau -- in and around southern China and northern Vietnam -- has been historically small.

"Surface uplift, caused by lower crustal flow, doesn't explain the evolution of regional river networks," says Hoke, referring to the process by which a river drainage system is diverted, or captured, from its own bed into that of a neighboring bed. "Our study suggests that river capture and drainage reorganization must have been the result of a slip on the major faults bounding the southeast plateau margin."

Hoke's discovery not only makes the plateau larger than previously thought, but also suggests that some of the topography is millions of years younger.

"Our data provides the first direct documentation of the magnitude and geographic extent of elevation change on the southeast margin of the Tibetan Plateau, tens of millions years ago," Hoke adds. "Constraining the age, spatial extent, and magnitude of ancient topography has a profound effect on how we understand the construction of mountain ranges and high plateaus, such as those in Tibet and the Altiplano region in Bolivia."

More From ScienceDaily

More Earth & Climate News

Featured Research

Mar. 31, 2015 — A better method for predicting the number of hurricanes in an upcoming season has been developed by atmospheric scientists. The team's new model improves the accuracy of seasonal hurricane forecasts ... full story

Mar. 31, 2015 — Soil organic matter, long thought to be a semi-permanent storehouse for ancient carbon, may be much more vulnerable to climate change than previously thought. Scientists have found that the common ... full story

Mar. 31, 2015 — The ocean is a large reservoir of dissolved organic molecules, and many of these molecules are stable against microbial utilization for hundreds to thousands of years. They contain a similar amount ... full story

Mar. 31, 2015 — Using the assessment tool ForWarn, US Forest Service researchers can monitor the growth and development of vegetation that signals winter's end and the awakening of a new growing season. Now these ... full story

Mar. 31, 2015 — Geoscientists have revealed information about how continents were generated on Earth more than 2.5 billion years ago -- and how those processes have continued within the last 70 million years to ... full story

Mar. 31, 2015 — Until now electric fences and trenches have proved to be the most effective way of protecting farms and villages from night time raids by hungry elephants. But researchers think they may have come up ... full story

Mar. 31, 2015 — The volcanologist Stephen Self, an expert on super-eruptions, was the first modern-day scientist to visit Tambora in Indonesia, the site of the largest volcanic eruption in 1,000 years. On the 200th ... full story

Mar. 31, 2015 — Researchers have detected a human fingerprint deep in the Borneo rainforest in Southeast Asia. Cold winds blowing from the north carry industrial pollutants from East Asia to the equator, with ... full story

Mar. 31, 2015 — Landfills can make a profit from all their rotting waste and a new patent explains exactly how to make the most out of the stinky garbage sites. Decomposing trash produces methane, a landfill gas ... full story

Mar. 31, 2015 — As the five-year anniversary of the explosion of the Deepwater Horizon oil rig approaches, a new report looks at how twenty species of wildlife are faring in the aftermath of the ... full story

Related Stories

Mar. 19, 2015 — Unaweep Canyon is a puzzling landscape -- the only canyon on Earth with two mouths. First formally documented by western explorers mapping the Colorado Territory in the 1800s, Unaweep Canyon has ... full story

Jan. 16, 2014 — Glaciers are important indicators of climate change. Global warming causes mountain glaciers to melt, which, apart from the shrinking of the Greenlandic and Antarctic ice sheets, is regarded as one ... full story

Mar. 8, 2012 — Drought events are largely unknown in Earth's history, because reconstruction of ancient hydrological conditions remains difficult due to lack of proxy. New research uses a microbial lipid proxy ... full story

Nov. 14, 2011 — Fine silt on the Chinese Loess Plateau may actually have come from due west, not the northwest, which would change conventional thinking about wind patterns over the last 2.6 million ... full story

Mar. 3, 2011 — New research shows that soot from industrial and agricultural pollution is landing on the Tibetan Plateau is causing snow to melt earlier on the plateau. As a result, India and China are experiencing ... full story

ScienceDaily features breaking news and videos about the latest discoveries in health, technology, the environment, and more -- from major news services and leading universities, scientific journals, and research organizations.